In the following, we propose a method for estimating the absolute phonetic duration given: (i) the score, and (ii) the phonemes duration histograms computed from the audio dataset annotations. First, we omit silence parts in the query audio (with a simple voice activity detection method [1]}) and also in the score by removing the rest notes. Second, we compute the duration histogram and its duration centroid for each phoneme class – by aggregating the phonetic durations indicated in the boundary annotations of the audio training dataset.
Then, we segment each syllabic duration in the score dataset into phonetic durations according to the proportion of their duration centroids. Finally, as the scores do not contain tempo, we normalize the phonetic durations of each phrase such that their summation is equal to the duration of the query audio. See fig:phonemeduration for an equivalent graphic explanation.
In fig:phonemeduration, the centroid durations of these three phonemes are: 0.46s, 0.9s and 0.1s, summing: 1.46s – alternatively, these can be expressed as a proportion of 1.46s: 0.32, 0.62 and 0.06. With these proportions and the absolute syllable duration (2s), we can compute the absolute phoneme durations: 0.32\(\cdot \) 2s = 0.64s, 0.62\(\cdot \) 2s=1.24s and 0.06\(\cdot \) 2s=0.12s.
